package chixing.day03;

import java.util.Arrays;

public class ArrayDemo {
    public static void main(String[] args) {
        int[] arr = {61, 19, 56, 37, 20, 66, 50, 34, 37, 3};
        quickSort(arr, 0, arr.length - 1);
        for (int i = 0; i < arr.length; i++) {
            System.out.print(arr[i] + " ");
        }
    }

    public static void bubboSort(int[] arr) {

        for (int i = 0; i < arr.length - 1; i++) {
            for (int j = 0; j < arr.length - 1 - i; j++) {
                if (arr[j] > arr[j + 1]) {
                    int temp = arr[j];
                    arr[j] = arr[j + 1];
                    arr[j + 1] = temp;
                }
            }
        }
        for (int i = 0; i < arr.length; i++) {
            System.out.print(arr[i] + " ");
        }
    }

    public static void selectSort(int[] arr) {

        for (int i = 0; i < arr.length - 1; i++) {
            int minIndex = i;
            for (int j = i + 1; j < arr.length; j++) {
                if (arr[j] < arr[minIndex]) {
                    minIndex = j;
                }
            }
            if (minIndex != i) {
                int temp = arr[i];
                arr[i] = arr[minIndex];
                arr[minIndex] = temp;
            }
        }
        for (int i = 0; i < arr.length; i++) {
            System.out.print(arr[i] + " ");
        }
    }

    public static void quickSort(int[] arr, int low, int high) {
        int i, j, temp, t;
        if (low > high) {
            return;
        }
        i = low;
        j = high;
// temp就是基准位
        temp = arr[low];
        while (i < j) {
// 先看右边，依次往左递减
            while (temp <= arr[j] && i < j) {
                j--;
            }
// 再看左边，依次往右递增
            while (temp >= arr[i] && i < j) {
                i++;
            }
// 如果满足条件则交换
            if (i < j) {
                t = arr[j];
                arr[j] = arr[i];
                arr[i] = t;
            }
        }
// 最后将基准为与i和j相等位置的数字交换
        arr[low] = arr[i];
        arr[i] = temp;
// 递归调用左半数组
        quickSort(arr, low, j - 1);
// 递归调用右半数组
        quickSort(arr, j + 1, high);
    }
}

